Systems and tools for use with surgical robotic manipulators

ABSTRACT

A tool for use with a surgical robotic manipulator that comprises an energy applicator including a shaft extending along an axis between a proximal end and a distal end. The shaft has an axial-force receiving surface. A tool assembly comprises a support structure to support the energy applicator, an axial connector assembly arranged to engage and releasably lock the energy applicator to the support structure in a locked state, a drive system coupled to the support structure to rotatably drive the shaft of the energy applicator about the axis, a collet assembly cooperating with the axial connector assembly and configured to apply a force to the axial-force receiving surface of the energy applicator in the locked state, and a reference surface. The force includes an axial component directing the energy applicator proximally into continuous contact with the reference surface in the locked state.

TECHNICAL FIELD

The subject patent application claims priority to and all the benefitsof U.S. Provisional Patent Application No. 62/411,039 which was filed onOct. 21, 2016, the disclosure of which is hereby incorporated byreference.

TECHNICAL FIELD

The present invention relates, generally, to surgical tools and, moreparticularly, to systems and tools for use with surgical roboticmanipulators.

BACKGROUND

Medical practitioners have found it useful to use surgical roboticmanipulators to assist in the performance of surgical procedures. Anexample of an end effector for a surgical robotic manipulator isdisclosed in U.S. Patent Application Publication No. 2014/0276949. Thereis a need in the art to continuously improve such end effectors.

SUMMARY

The present disclosure provides a tool that comprises an energyapplicator including a shaft extending along an axis between a proximalend and a distal end. The shaft has an axial-force receiving surface. Atool assembly comprises a support structure to support the energyapplicator, an axial connector assembly arranged to engage andreleasably lock the energy applicator to the support structure in alocked state, a drive system coupled to the support structure torotatably drive the shaft of the energy applicator about the axis, acollet assembly cooperating with the axial connector assembly andconfigured to apply a force to the axial-force receiving surface of theenergy applicator in the locked state, and a reference surface. Theforce includes an axial component directing the energy applicatorproximally into continuous contact with the reference surface in thelocked state.

The present disclosure also provides a tool assembly for use with anenergy applicator having a shaft extending along an axis between aproximal end and a distal end, the shaft having an axial-force receivingsurface. The tool assembly comprises a support structure to support theenergy applicator, an axial connector assembly arranged to engage andreleasably lock the energy applicator to the support structure in alocked state, a drive system coupled to the support structure torotatably drive the shaft of the energy applicator about the axis, acollet assembly cooperating with the axial connector assembly andconfigured to apply a force to the axial-force receiving surface of theenergy applicator when the axial connector assembly engages andreleasably locks the energy applicator to the support structure in thelocked state, and a reference surface. The force includes an axialcomponent directing the energy applicator proximally into continuouscontact with the reference surface in the locked state.

The present disclosure also provides a tool comprising an energyapplicator including a shaft extending along an axis between a proximalend and a distal end. A tool assembly comprises a support structure tosupport the energy applicator, a connector assembly arranged to engageand releasably lock the energy applicator to the support structure in alocked state, and a drive system coupled to the support structure andconfigured to rotatably drive the shaft of the energy applicator aboutthe axis. A protective sheath is releasably coupled to the toolassembly, wherein the protective sheath is arranged concentrically aboutthe shaft of the energy applicator between the distal end of the shaftand the connector assembly. The connector assembly has a connectormember to facilitate releasable coupling of the protective sheath to thetool assembly.

The present disclosure also provides a protective sheath assembly foruse with a tool assembly and an energy applicator extending from thetool assembly. The protective sheath assembly comprises a protectivesheath configured to be releasably coupled to the tool assembly so thatthe protective sheath is arranged concentrically about the shaft of theenergy applicator. A bearing is supported in the protective sheath suchthat the bearing is releasable, along with the protective sheath, fromthe tool assembly.

The present disclosure also provides a tool comprising an energyapplicator including a shaft extending along an axis between a proximalend and a distal end. A tool assembly comprises a support structure tosupport the energy applicator, a connector assembly arranged to engageand releasably lock the energy applicator to the support structure in alocked state, and a drive system coupled to the support structure andconfigured to rotatably drive the shaft of the energy applicator aboutthe axis. The drive system comprises a counterweighted clutch assembly.

The present disclosure also provides a tool assembly for use with anenergy applicator having a shaft extending along an axis between aproximal end and a distal end. The tool assembly comprises a supportstructure to support the energy applicator, a connector assemblyarranged to engage and releasably lock the energy applicator to thesupport structure in a locked state, and a drive system coupled to thesupport structure and configured to rotatably drive the shaft of theenergy applicator about the axis. The drive system comprises acounterweighted clutch assembly.

The present disclosure also provides an energy applicator for use with atool assembly. The energy applicator comprises a shaft extending alongan axis from a proximal end to a distal end. The shaft has anaxial-force receiving surface for receiving an axial component of forcefrom the tool assembly directing the shaft proximally into continuouscontact with a reference surface of the tool assembly. The energyapplicator also comprises a working portion located at the distal endfor treating tissue of a patient.

Other features and advantages of the present disclosure will be readilyappreciated, as the same becomes better understood, after reading thesubsequent description taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surgical robotic system including asurgical robotic manipulator and an end effector performing a surgicalprocedure on a patient.

FIG. 2 is a perspective view of one embodiment of the end effectorcomprising a surgical tool.

FIG. 3 is an exploded view of the surgical tool.

FIG. 4 is an exploded view of an energy applicator, a protective sheath,and an axial connector assembly.

FIG. 5 is a perspective view of the energy applicator, protectivesheath, and axial connector assembly of FIG. 4.

FIG. 6 is an exploded view of the energy applicator, protective sheath,and axial connector assembly of FIG. 4 already pre-assembled and asupport structure.

FIG. 7 is a perspective view of the energy applicator, protectivesheath, axial connector assembly, and the support structure of FIG. 6.

FIG. 8 is an elevational view of the energy applicator, protectivesheath, axial connector assembly, and the support structure of FIG. 6.

FIG. 9 is a cross-sectional view taken along line 9-9 of FIG. 8.

FIG. 10 is an enlarged view of a portion of FIG. 9.

FIG. 11 is a perspective view of the energy applicator, protectivesheath, and a tool assembly, the tool assembly comprising the axialconnector assembly, the support structure, and a collet assembly.

FIG. 12 is another perspective view of the energy applicator, protectivesheath, and the tool assembly of FIG. 11.

FIG. 13 is an elevational view of the energy applicator, protectivesheath, and the tool assembly of FIG. 11.

FIG. 14 is a cross-sectional view taken along line 14-14 of FIG. 13.

FIG. 15 is an exploded view of the collet assembly illustrating theenergy applicator, protective sheath, the axial connector assembly, andthe support structure being pre-assembled.

FIG. 16 is an exploded view of a drive assembly of the surgical tool.

FIG. 17 is an exploded view of a clutch assembly of the drive assemblyof FIG. 16.

FIG. 18 is an elevational view of the drive assembly of FIG. 16.

FIG. 19 is a cross-sectional view taken along line 19-19 of FIG. 18.

FIG. 20 is a cross-sectional view taken along line 20-20 of FIG. 18.

FIG. 21 is another cross-sectional view showing the energy applicator,protective sheath, axial connector assembly, support structure, colletassembly, and drive assembly.

FIG. 22 is a partial perspective view of another embodiment of an endeffector, a surgical tool, and an energy applicator, the surgical toolshown having a trigger arranged in a depressed position, and shownhaving a connector assembly arranged in a locked state.

FIG. 23 is another partial perspective view of the end effector,surgical tool, and energy applicator of FIG. 22, shown with the triggerarranged in a released position, and shown with the connector assemblyarranged in an unlocked state.

FIG. 24A is a broken sectional view of a portion of the surgical tooland energy applicator taken along line 24-24 in FIG. 22, shown with thetrigger arranged in the depressed position, and shown with the connectorassembly arranged in the locked state.

FIG. 24B is another partial broken sectional view of the surgical tooland energy applicator of FIG. 24A, shown with the trigger arranged in areleased position, and shown with the connector assembly arranged in thelocked state.

FIG. 24C is another partial broken sectional view of the surgical tooland energy applicator of FIGS. 24A-24B, shown with the trigger arrangedin the released position, and shown with the connector assembly arrangedin an unlocked state.

FIG. 25A is a broken sectional view of a portion of the surgical tooland energy applicator taken along line 25-25 in FIG. 22, shown with thetrigger arranged in the depressed position, and shown with the connectorassembly arranged in the locked state.

FIG. 25B is another partial broken sectional view of the surgical tooland energy applicator of FIG. 25A, shown with the trigger arranged in areleased position, and shown with the connector assembly arranged in thelocked state.

FIG. 25C is another partial broken sectional view of the surgical tooland energy applicator of FIGS. 25A-25B, shown with the trigger arrangedin the released position, and shown with the connector assembly arrangedin an unlocked state.

Certain of the Figures set forth above may have portions of the endeffector removed for purposes of illustration.

DETAILED DESCRIPTION

Referring now to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a system 10 formanipulating an anatomy of a patient 12 are shown throughout. As shownin FIG. 1, the system 10 is a robotic surgical cutting system forcutting away material from the anatomy of the patient 12, such as boneor soft tissue. In FIG. 1, the patient 12 is undergoing a surgicalprocedure, and the anatomy includes a femur (F) and a tibia (T) of thepatient 12. The surgical procedure may involve tissue removal. In someembodiments, the surgical procedure involves partial or total knee orhip replacement surgery. The system 10 is designed to cut away materialto be replaced by surgical implants such as hip and knee implants,including unicompartmental, bicompartmental, total knee implants, andother types of prosthetics. Some of these types of implants aredisclosed in U.S. Patent Application Publication No. 2012/0330429,entitled, “Prosthetic Implant and Method of Implantation,” the entiredisclosure of which is hereby expressly incorporated by reference. Itshould be appreciated that the system 10 disclosed herein may be used toperform other procedures, either surgical or non-surgical, and/or may beused in industrial applications or other applications.

The system 10 includes a surgical manipulator 14 (e.g., a surgicalrobot). The manipulator 14 has a base 16 and a linkage 18 (e.g., anarticulable robotic arm). The linkage 18 may include links forming aserial arm or parallel arm configuration. A tool 20 couples to themanipulator 14 and is movable relative to the base 16 via the linkage 18to interact with the anatomy of the patient 12. The tool 20 forms partof an end effector 22 attached to the manipulator 14. The tool 20 isgrasped by the operator (e.g., a surgeon) in some embodiments. Oneexemplary arrangement of the manipulator 14 and the tool 20 is describedin U.S. Pat. No. 9,119,655, entitled, “Surgical Manipulator Capable ofControlling a Surgical Instrument in Multiple Modes,” the entiredisclosure of which is hereby expressly incorporated by reference. Themanipulator 14 and the tool 20 may be arranged in alternativeconfigurations. The tool 20 comprises an energy applicator 24 to contactthe tissue of the patient 12 at a surgical site. The energy applicator24 may be a drill, a saw blade, a bur, an ultrasonic vibrating tip, orthe like. Other configurations are contemplated. The manipulator 14houses a manipulator computer 26, or other type of control unit.

The system 10 includes a controller which includes software and/orhardware for controlling the manipulator 14. The controller directs themotion of the manipulator 14 and controls a position and orientation ofthe tool 20 with respect to a coordinate system. In one embodiment, thecoordinate system is a manipulator coordinate system MNPL (see FIG. 1).The manipulator coordinate system MNPL has an origin, and the origin islocated relative to the manipulator 14. One example of the manipulatorcoordinate system MNPL is described in U.S. Pat. No. 9,119,655,entitled, “Surgical Manipulator Capable of Controlling a SurgicalInstrument in Multiple Modes,” previously referenced.

The system 10 further includes a navigation system 32. One example ofthe navigation system 32 is described in U.S. Pat. No. 9,008,757, filedon Sep. 24, 2013, entitled, “Navigation System Including Optical andNon-Optical Sensors,” the entire disclosure of which is hereby expresslyincorporated by reference. The navigation system 32 is set up to trackmovement of various objects. Such objects include, for example, the tool20, and the anatomy, e.g., femur F and tibia T. The navigation system 32tracks these objects to gather position information of each object in alocalizer coordinate system LCLZ. Coordinates in the localizercoordinate system LCLZ may be transformed to the manipulator coordinatesystem MNPL using conventional transformation techniques. In someembodiments, the navigation system 32 is also capable of displaying avirtual representation of their relative positions and orientations tothe operator.

The navigation system 32 includes a computer cart assembly 34 thathouses a navigation computer 36, and/or other types of control units. Anavigation interface is in operative communication with the navigationcomputer 36. The navigation interface includes one or more displays 38.First and second input devices 40, 42 such as touch screen inputs may beused to input information into the navigation computer 36 or otherwiseselect/control certain aspects of the navigation computer 36. Otherinput devices are contemplated, including a keyboard, mouse,voice-activation, and the like. The controller may be implemented on anysuitable device or devices in the system 10, including, but not limitedto, the manipulator computer 26, the navigation computer 36, and anycombination thereof.

The navigation system 32 also includes a localizer 44 that communicateswith the navigation computer 36. In one embodiment, the localizer 44 isan optical localizer and includes a camera unit 46. The camera unit 46has an outer casing 48 that houses one or more optical position sensors50. The system 10 also includes one or more trackers. The trackers mayinclude a pointer tracker PT, a tool tracker 52, a first patient tracker54, and a second patient tracker 56. The trackers include active markers58. The active markers 58 may be light emitting diodes or LEDs. In otherembodiments, the trackers 52, 54, 56 may have passive markers, such asreflectors, which reflect light emitted from the camera unit 46. Itshould be appreciated that other suitable tracking systems and methodsnot specifically described herein may be utilized.

In the illustrated embodiment of FIG. 1, the first patient tracker 54 isfirmly affixed to the femur F of the patient 12 and the second patienttracker 56 is firmly affixed to the tibia T of the patient 12. Thepatient trackers 54, 56 are firmly affixed to sections of bone. The tooltracker 52 is firmly attached to the tool 20. It should be appreciatedthat the trackers 52, 54, 56 may be fixed to their respective componentsin any suitable manner.

The trackers 52, 54, 56 communicate with the camera unit 46 to provideposition data to the camera unit 46. The camera unit 46 provides theposition data of the trackers 52, 54, 56 to the navigation computer 36.In one embodiment, the navigation computer 36 determines andcommunicates position data of the femur F and tibia T and position dataof the tool 20 to the manipulator computer 26. Position data for thefemur F, tibia T, and tool 20 may be determined by the tracker positiondata using conventional registration/navigation techniques. The positiondata include position information corresponding to the position and/ororientation of the femur F, tibia T, tool 20, and/or any other objectsbeing tracked. The position data described herein may be position data,orientation data, or a combination of position data and orientationdata.

The manipulator computer 26 transforms the position data from thelocalizer coordinate system LCLZ into the manipulator coordinate systemMNPL by determining a transformation matrix using the navigation-baseddata for the tool 20 and encoder-based position data for the tool 20.Encoders (not shown) located at joints of the manipulator 14 are used todetermine the encoder-based position data. The manipulator computer 26uses the encoders to calculate an encoder-based position and orientationof the tool 20 in the manipulator coordinate system MNPL. Since theposition and orientation of the tool 20 are also known in the localizercoordinate system LCLZ, the transformation matrix may be generated.

In one embodiment, the controller includes a manipulator controller 60for processing data to direct motion of the manipulator 14. Themanipulator controller 60 may receive and process data from a singlesource or from multiple sources.

The controller further includes a navigation controller 62 forcommunicating the position data relating to the femur F, tibia T, andtool 20 to the manipulator controller 60. The manipulator controller 60receives and processes the position data provided by the navigationcontroller 62 to direct movement of the manipulator 14. In oneembodiment, as shown in FIG. 1, the navigation controller 62 isimplemented on the navigation computer 36.

The manipulator controller 60 or navigation controller 62 may alsocommunicate positions of the patient 12 and the tool 20 to the operatorby displaying an image of the femur F and/or tibia T and the tool 20 onthe display 38. The manipulator computer 26 or navigation computer 36may also display instructions or request information on the display 38such that the operator may interact with the manipulator computer 26 fordirecting the manipulator 14. Other configurations are contemplated.

Referring to FIG. 2, in some embodiments, the tool 20 includes a drivesystem 66 that converts electrical signals into a form of energy that isapplied to the patient. This energy may be mechanical, ultrasonic,thermal, RF, EM, photonic, combinations thereof, and the like. Theenergy is applied to the patient 12 through the energy applicator 24. Inthe representative embodiment shown, the end effector 22 includes amounting fixture 64 for removably attaching the tool 20 to themanipulator 14. In the embodiment shown, the energy applicator 24 isconfigured to remove tissue of the patient. As shown in the Figures, theenergy applicator 24 comprises a bur. Alternative to a bur, the energyapplicator 24 may comprise any type of surgical tool for materialcutting, material removal, or other tissue manipulation or treatment ata surgical site.

With reference to FIGS. 3 and 4, in the embodiment shown, the energyapplicator 24 includes a working portion comprising a head 68 forcutting tissue of the patient 12, and a shaft 70 extending along a toolaxis T between a proximal end 72 and a distal end 74. The shaft 70includes an outer surface 71 in which an annular groove or recess 76 isdisposed. The groove or recess 76 is arranged axially between theproximal end 72 and the distal end 74, and extends radially inwardtoward the tool axis T to a bottom 73. Put differently, the groove orannular recess 76 depends inwardly from the outer surface 71 to thebottom 73. As is explained in greater detail below, the groove orannular recess 76 at least partially defines an axial-force receivingsurface to promote axial retention of the energy applicator 24.

The groove or annular recess 76 has a distal surface 75 and a slopedsurface 77, each of which extends from the outer surface 71 of the shaft70 to the bottom 73. In the illustrated embodiment, the distal surface75 has a generally toroidal profile and is arranged axially between thedistal end 74 and the bottom 73, and the sloped surface 77 has agenerally conical profile and is arranged axially between the bottom 73and the proximal end 72. As shown in FIG. 4, the conical, sloped surface77 is formed extending along a first axial distance AD1 from the outersurface 71 to the bottom 73, and the distal surface 75 is formedextending along a second axial distance AD2, less than the first axialdistance AD1, from the outer surface 71 to the bottom 73. It will beappreciated that the annular groove or recess 76 could have differentconfigurations sufficient to promote axial retention of the energyapplicator 24.

The conical, sloped surface 77 is arranged at an acute angle α₁ relativeto the axis T (see FIG. 10). In some embodiments, the acute angle α₁ isgreater than zero degrees and less than 90 degrees. In otherembodiments, the acute angle α₁ is 5-60 degrees, 10-30 degrees, or 10-20degrees, relative to the axis T. The shaft 70 may include a passage 78(see FIG. 9) extending axially between the proximal end 72 and thedistal end 74 for purposes of irrigation and/or suction. In theembodiment shown, the head 68 and shaft 70 of the energy applicator 24are integral, unitary, and one-piece, but could be separate parts inother embodiments.

Referring to FIG. 4 through 10, a protective sheath 80 supports theenergy applicator 24. The protective sheath 80 comprises a nose tube 81and defines a protective sheath bore 82 (see FIG. 9) and receives theshaft 70 of the energy applicator 24 in the protective sheath bore 82.The protective sheath 80 includes an enlarged end portion 84 which isconfigured for releasable attachment, as is described in greater detailbelow. The nose tube 81 is formed integrally with and extends from theend portion 84, and a distal bushing 83 is attached to the distal end ofthe nose tube 81. The distal bushing 83 is configured to beconcentrically disposed about the shaft 70 of the energy applicator 24.As is depicted in FIG. 4, the distal bushing 83 has a first innerdiameter ID1, and the nose tube 81 has a second inner diameter ID2 whichis larger than the first inner diameter ID2. Here too in FIG. 4, the endportion 84 has a first outer diameter OD1 and the nose tube 81 has asecond outer diameter OD2 which is smaller than the first outer diameterOD2.

The enlarged end portion 84 has a cavity 86 and at least one bearing 88,shown for example in FIG. 10, disposed in the cavity 86. In someembodiments, the protective sheath 80 and the bearing 88 form areleasably attachable protective sheath assembly 87 (see FIG. 4). Thebearing 88 is configured to receive and rotatably support the shaft 70in the protective sheath bore 82. The enlarged end portion 84 has one ormore outer grooves 90 extending axially. The grooves 90 arecircumferentially and equally spaced about an outer periphery of theenlarged end portion 84. The grooves 90 are spaced circumferentiallyabout the outer surface and extend from a proximal end of the enlargedend portion 84 to a detent pocket 91. In the illustrated embodiments,the grooves 90 are shallower than their corresponding detent pockets 91,and extend axially from the respective detent pockets 91 to the proximalend of the end portion 84 of the protective sheath 80. However, it willbe appreciated that other configurations are contemplated.

An axial connector assembly 92 couples the energy applicator 24 and theprotective sheath 80 to a support structure 94 (see FIG. 6). As setforth further below, the connector assembly 92 supports the protectivesheath 80 and is configured to support or lock the energy applicator 24relative to the protective sheath 80. The axial connector assembly 92and the support structure 94 are concentrically disposed relative toeach other along the axis T. The axial connector assembly 92 releasablyengages the energy applicator 24 and the protective sheath 80 such thatboth of the energy applicator 24 and the protective sheath 80 arereplaceable components.

Referring to FIG. 10, in the illustrated embodiment, the supportstructure 94 includes a support sleeve 96 extending axially. The supportsleeve 96 is generally cylindrical in shape. The support sleeve 96 has ahollow interior cavity 98 with a plurality of internal threads 100 at adistal end thereof. The axial connector assembly 92 includes a connectormember 102 to facilitate releasable connection of the protective sheath80 to the support sleeve 96. The connector member 102 includes aplurality of exterior threads 112 to threadably engage the interiorthreads 100 of the support sleeve 96. The connector member 102 isgenerally cylindrical in shape.

The connector member 102 includes an interior wall 104 extendingradially inwardly to act as a stop for the enlarged end portion 84 ofthe protective sheath 80 when inserting the protective sheath 80 intothe connector member 102. The interior wall 104 has an aperture 106extending axially therethrough to allow the shaft 70 of the energyapplicator 24 to extend therethrough. The connector member 102 includesa flange 108 extending radially outward to engage an interior surface ofthe support sleeve 96.

The connector member 102 also includes one or more openings 110 (seealso FIG. 4) extending radially therethrough. The openings 110 aredisposed axially between the interior wall 104 and the flange 108. Inthe embodiment shown, the connector member 102 is integral, unitary, andone-piece, but could be separate parts in other embodiments.

The axial connector assembly 92 also includes at least one engagementmember 114 to releasably couple the protective sheath 80 to theconnector member 102. In one embodiment, a plurality of engagementmembers 114 are used with one engagement member 114 disposed in eachopening 110. Each of the engagement members 114 is generally sphericalin shape. In the embodiment shown, the engagement members 114 are ballbearings, such as those formed of stainless steel or other suitablematerials. The axial connector assembly 92 can include any number ofengagement members 114 and corresponding openings 110.

The axial connector assembly 92 also includes a resilient member 116disposed about the engagement members 114. The resilient member 116 maybe an O-ring seal, but may have other forms, such as a compressionspring or other type of spring. The resilient member 116 presses theengagement members 114 into their corresponding openings 110 tofacilitate a releasable connection to the enlarged end portion 84 of theprotective sheath 80.

Each of the openings 110 are sized and shaped so that the engagementmembers 114 are capable of being exposed on either side of the openings110. By being exposed on a radially outward side of the openings 110,the resilient member 116 can apply a biasing force to the engagementmembers 114. By being exposed on a radially inward side of the openings110, the engagement members 114 are able to engage the enlarged endportion 84 of the protective sheath 80. The openings 110 may be sizedand shaped to receive the engagement members 114 without allowing theengagement members 114 to fall through the openings 110 when theprotective sheath 80 is absent. For instance, the openings 110 could betapered radially inwardly to a diameter sized to retain the engagementmembers 114.

When axially coupling the protective sheath 80 to the connector member102 (which is already fixed to the support sleeve 96), the engagementmembers 114 are sized and shaped to move along and within the grooves 90defined in the enlarged end portion 84, under constant bias of theresilient member 116 until the engagement members 114 reach (e.g., areradially aligned with) the detent pockets 91. At that point, theengagement members 114 are seated in the detent pockets 91 therebyholding the protective sheath 80 to the connector member 102 by virtueof the bias associated with the resilient member 116. The protectivesheath 80 may be removed by pulling on the protective sheath 80 distallyto overcome the bias and urge the engagement members 114 out from thedetent pockets 91.

The protective sheath 80 may require replacement when the bearing 88 isworn. Accordingly, by having the bearing 88 supported in the protectivesheath 80 and making the protective sheath 80 removable and replaceable,significant down time can be avoided that might otherwise exist if theentire end effector 22 needed to be taken out of circulation to replacethe bearing 88.

The protective sheath 80 defines one or more weep holes 99 extendingradially therethrough. The weep holes 99 may be spaced axially and/orcircumferentially about the protective sheath 80. In the embodimentshown, a first pair of diametrically opposing weep holes 99 are locatednear the enlarged end portion 84 of the protective sheath 80 at a firstaxial distance from the enlarged end portion 84. A second pair ofdiametrically opposing weep holes 99 are located further away from theenlarged end portion 84 at a second axial distance. The second pair ofweep holes 99 are also located on the protective sheath 80 withapproximately 90 degrees of circumferential separation from the firstpair of weep holes 99. The weep holes 99 are intended to prevent fluidfrom the surgical site coming into contact with the bearing 88, whichmay otherwise shorten the operational life of the bearing 88. Duringuse, and owing to temperature gradients in the tool 20 and capillaryeffects, fluid may tend to move between the shaft 70 of the energyapplicator 24 and the protective sheath 80 toward the bearing 88. Theweep holes 99 provide a suitable escape for such fluid before it reachesthe bearing 88.

Still referring to FIG. 10, the axial connector assembly 92 includes abushing 118 disposed within the connector member 102 at a proximal endof the connector member 102. The bushing 118 is generally cylindrical inshape with an aperture 120 extending axially therethrough. In someembodiments, the bushing 118 is fixed axially to the support sleeve 96and/or the connector member 102. Alternatively, the bushing 118 may befloating within the support sleeve 96.

The axial connector assembly 92 further includes a cam member 122. Thecam member 122 can also be referred to as a wedge member. The cam member122 includes a reduced diameter portion 124 disposed in the aperture 120of the bushing 118 to rotate relative to the support sleeve 96. The cammember 122 rotates relative to the support sleeve 96. The cam member 122includes a cavity 126 extending axially from the proximal end thereof.The cavity 126 includes a tapered or sloped surface 128 (also referredto as a cam surface or a wedge surface) extending axially and radiallyinward. In the embodiment shown, the sloped surface 128 is in the formof a conical surface. The sloped surface 128 is arranged at an acuteangle α₂ relative to the tool axis T. In some embodiments, the slopedsurface 128 is at an acute angle α₂ greater than zero degrees and lessthan 90 degrees. In other embodiments, the acute angle α₂ is 5-60degrees, 10-30 degrees, or 10-20 degrees, relative to the axis T. Theacute angles α₁ and α₂ are sized so that at least one engagement member138, described further below, becomes wedged between the sloped surfaces77, 128 to hold the shaft 70 of the energy applicator 24, yet is readilyreleasable from the shaft 70. The difference in the acute angles α₁ andα₂ may be 4-12 degrees, 6-10 degrees, 7-9 degrees, or 8 degrees relativeto the axis T.

The axial connector assembly 92 includes a locking sleeve 130 disposedwithin the support sleeve 96. The locking sleeve 130 extends axially.The locking sleeve 130 is generally cylindrical in shape. The lockingsleeve 130 has a passage 132 extending axially therethrough to receivethe shaft 70. The locking sleeve 130 also includes a plurality ofopenings 134 extending radially therethrough near a distal end thereofto receive the engagement members 138. The openings 134 are sized andshaped to allow the engagement members 138 to be exposed radiallyinwardly relative to the locking sleeve 130 to engage the sloped surface79. The openings 134 are also sized and shaped to allow the engagementmembers 138 to be exposed radially outwardly relative to the lockingsleeve 130 to engage the sloped surface 128. The openings 134 may besized and shaped to prevent the engagement members 138 from passingcompletely through the openings 134 thereby retaining the engagementmembers 138. The locking sleeve 130 includes a flange 136 extendingradially outwardly. In the embodiment shown, the locking sleeve 130 isintegral, unitary, and one-piece, but could be separate parts in otherembodiments.

The engagement members 138 couple the shaft 70 to the cam member 122. Inone embodiment, a plurality of engagement members 138 are used with oneengagement member 138 disposed in each opening 134 of the locking sleeve130. Each of the engagement members 138 is generally spherical in shape.It should be appreciated that the axial connector assembly 92 mayinclude any number of engagement members 138 and corresponding openings134. In the embodiment shown, the engagement members 138 are ballbearings, such as those formed of stainless steel or other suitablematerials.

The axial connector assembly 92 also includes a bushing 140 disposedabout the locking sleeve 130 and within the support sleeve 96. Thebushing 140 is generally cylindrical in shape with an aperture 142extending axially therethrough to allow the locking sleeve 130 to extendtherethrough. The bushing 140 is fixed relative to the support sleeve 96in the embodiment shown. In other embodiments, the bushing 140 is freeto float within the support sleeve 96 between the cam member 122 and thelocking sleeve 130.

The axial connector assembly 92 further includes a ring member 144disposed about the locking sleeve 130 between the bushing 140 and theflange 136. The ring member 144 is generally cylindrical in shape. Thering member 144 has one or more pockets 145 extending radially therein.In one embodiment, a pair of opposed pockets 145 extend radiallytherein.

The support structure 94 includes one or more slots 146 in the supportsleeve 96. The slots 146 extend radially therethrough and are arrangedhelically about an axis of the support sleeve 96. In the embodimentshown, opposing slots 146 are formed helically in the support sleeve 96.The slots 146 in the embodiment shown are located only partially aboutthe support sleeve 96. The support structure 94 also includes one ormore engagement members 148 disposed in the slots 146 and pockets 145 ofthe ring member 144. One of the engagement members 148 is disposed ineach of the slots 146 and pockets 145. In the embodiment shown, theengagement members 148 are ball bearings, such as those formed ofstainless steel or other suitable materials. However, otherconfigurations are contemplated.

With reference to FIGS. 11-15, a collet assembly 157 cooperates with thesupport structure 94 to move the axial connector assembly 92 betweenlocked and unlocked states. The collet assembly 157 includes a lockcollar 158 which is movable relative to the support structure 94. Thelock collar 158 is elongated axially. The lock collar 158 is generallycylindrical in shape. The lock collar 158 is disposed about a portion ofthe support sleeve 96 of the support structure 94.

Referring to FIGS. 14 and 15, the lock collar 158 includes a wall 160that defines cutouts 162 spaced circumferentially about the wall 160 andextending axially. The lock collar 158 includes one or more recesses 164(see FIG. 15) extending axially inward from the distal end. The lockcollar 158 also includes one or more pockets 165 (only one shown in FIG.15) at a distal end extending axially inward. The collet assembly 157also includes a release member coupled to the lock collar 158 which isconfigured to be actuated by the user to move the lock collar 158, suchas to place the connector assembly 92 in the unlocked state. To thisend, and in the embodiment illustrated in FIG. 15, the release membercomprises a gripping member 166 at a proximal end of the lock collar 158to be grasped by a user. The gripping member 166 is generallycylindrical in shape. It should be appreciated that the lock collar 158may be rotated relative to the support sleeve 96 of the supportstructure 94.

The collet assembly 157 also includes a spring member 168 disposedwithin the lock collar 158. The spring member 168 extends axially. Inthe embodiment shown, the spring member 168 is a helical torsion spring.The spring member 168 is generally cylindrical in shape. The springmember 168 includes a plurality of convolutions 170. The spring member168 includes at least one or more distal tabs 172 extending axially at adistal end. The distal tabs 172 are disposed inside the opposing pockets165 of the lock collar 158 and are fixed to the lock collar 158. Thespring member 168 includes at least one or more proximal tabs 174extending axially at a proximal end.

The collet assembly 157 includes a first collar member 176 disposed overthe support sleeve 96 of the support structure 94. The first collarmember 176 is generally cylindrical in shape. The first collar member176 includes a plurality of protrusions 178 extending axially andradially outward and a plurality of recesses 179 (one partially shown inFIG. 15) extending axially inward from a proximal end. The first collarmember 176 also includes a recess 180 in two of the opposed protrusions178 to receive the tabs 174 of the spring member 168.

The collet assembly 157 further includes a second collar member 182disposed over the support sleeve 96 of the support structure 94. Thesecond collar member 182 is generally cylindrical in shape. The secondcollar member 182 includes a plurality of protrusions 184 extendingaxially and radially outward. The second collar member 182 includes oneor more recesses 186 extending axially through two of the opposedprotrusions 184. The collet assembly 157 further includes a bushing 185disposed against the flange 136 of the locking sleeve 130 to rotatablysupport the locking sleeve 130 in the support sleeve 96.

As illustrated, the axial connector assembly 92, support structure 94,and collet assembly 157 form a tool assembly 187. The tool assembly 187includes a coil spring 188 disposed within the support sleeve 96 of thesupport structure 94. The coil spring 188 has a distal end that abutsthe bushing 140. The tool assembly 187 includes a plurality of rods 190disposed in grooves 192 extending axially along an outer periphery ofthe support sleeve 96 of the support structure 94. The rods 190 are alsodisposed in the recesses 179 of the first collar member 176 and therecesses 186 of the second collar member 182. It should be appreciatedthat the rods 190 key and rotatably fix the first collar member 176 andthe second collar member 182 to the support sleeve 96.

In operation of the collet assembly 157, a user grasps the grippingmember 166 and rotates the lock collar 158 clockwise (when viewed fromthe distal end) to allow disengagement of the energy applicator 24. Asthe lock collar 158 is rotated, the rods 190 rotationally lock the firstcollar member 176 and the second collar member 182 to the support sleeve96. The lock collar 158 thus rotates against the bias of the springmember 168 (since the proximal end of the spring member 168 is preventedfrom rotating).

When rotating the lock collar 158, the engagement members 148 (e.g.,ball bearings) are also moved in the slots 146 by virtue of theengagement members 148 being coupled to the lock collar 158, i.e., theengagement members 148 are positioned within the recesses 164 located inthe distal end of the lock collar 158. Accordingly, movement of theengagement members 148 is controlled by rotation of the lock collar 158.Due to the helical nature of the slots 146, when moved by the lockcollar 158, the engagement members 148 follow their correspondinghelical paths such that the engagement members 148 are moved both in aplanetary fashion about the tool axis T and axially with respect to thetool axis T toward the proximal end of the support sleeve 96. The lockcollar 158 is configured to rotate, but not to translate relative to theaxis T. As a result, the recesses 164 are axially elongated, so that asthe lock collar 158 is rotated, and the engagement members 148 followthe helical paths in the slots 146, the engagement members 148 alsotranslate within the recesses 164. In other embodiments, the lock collar158 may also translate axially with the engagement members 148.

Axial movement of the ring member 144 is facilitated by the engagementmembers 148 being seated in the pockets 145 of the ring member 144 andcaptured between the pockets 145 and the recesses 164. In essence, thelock collar 158 is coupled to the ring member 144 through the engagementmembers 148. As a result, when the engagement members 148 are movedalong their helical paths in the slots 146, the ring member 144 followsthe engagement members 148 and is partially rotated and moved axiallytowards the flange 136. First, the ring member 144 reaches the flange136 of the locking sleeve 130, and thereafter moves the locking sleeve130 and associated bushing 185 proximally against the bias of spring188. The engagement members 138 that were wedged between the slopedsurfaces 77, 128 of the shaft 70 and the cam member 122 are therebyreleased from their wedged arrangement away from the sloped surface 77defining the groove 76 of the shaft 70 to unlock the shaft 70 and allowremoval of the energy applicator 24. This defines the unlocked state ofthe axial connector assembly 92. Since the slots 146 in the embodimentshown are only partially defined about the support sleeve 96, onlypartial rotation of the lock collar 158 is required to unlock the shaft70 and allow removal of the energy applicator 24. The rotation requiredmay be 180 degrees or less, 90 degrees or less, or 45 degrees or less.

When the gripping member 166 is released, the spring member 168 returnsto its normal state thereby moving the engagement members 148 in theslots 146 in a reverse direction along their helical paths, which movesthe ring member 144 distally to disengage the flange 136 of the lockingsleeve 130, which allows the spring 188 to push the locking sleeve 130back toward the cam member 122. The engagement members 138 fall backinto the groove 76 against the sloped surface 77 of the shaft 70 of theenergy applicator 24 and wedge against the sloped surface 128 to lockthe shaft 70. This defines the locked state of the axial connectorassembly 92. The collet assembly 157 operates the axial connectorassembly 92 between the locked and unlocked states.

It should be appreciated that, when the energy applicator 24 isconnected and locked to the tool assembly 187, the collet assembly 157cooperates with the axial connector assembly 92 to apply a force to keepthe proximal end 72 of the energy applicator 24 abutting against ashoulder 189 of the tool assembly 187. In particular, when theengagement members 138 are wedged between the sloped surfaces 77, 128,under the influence of the spring 188, these engagement members 138impart a force directed against the sloped surface 77 of the energyapplicator 24. This force includes an axial component applied againstthe energy applicator in the proximal direction to maintain the abuttingcontact between the proximal end 72 of the energy applicator 24 and theshoulder 189 (or other reference surface fixed relative to the supportstructure 94). Thus, the sloping surface 77 of the energy applicator 24may also be referred to as an axial-force receiving surface.

One purpose of the abutment between the proximal end 72 and the shoulder189 is to consistently match up and enable communication between anidentification tag (e.g., a radio frequency identification tag RFID) onthe energy applicator 24 and a radio frequency identification reader 199(FIG. 19) on the tool assembly 187. This engagement of the proximal end72 of the energy applicator and the shoulder 189 also providesrepeatability in establishing the location (e.g., position in X, Y, Zcoordinates) of a tool center point (TCP) of the energy applicator 24for purposes of surgical navigation as described herein. For instance,the location of the TCP may be calibrated during manufacture and thedetails of the calibration, e.g., calibration data, thereafter stored inthe RFID tag or other non-volatile memory for retrieval by a toolcontroller (not shown) that controls operation of the tool 20, themanipulator controller 60, and/or the navigation controller 62. Byvirtue of having a consistent interface (e.g., abutting contact) betweenthe tool assembly 187 and the energy applicator 24, the system 10 (whichincludes the navigation system 32) is capable of retrieving thecalibration data to readily determine the TCP in a coordinate system ofthe tool 20 or other coordinate system with high accuracy. Accordingly,the shoulder 189 provides a reference location from which to locate theTCP.

Referring to FIGS. 16-21, a drive assembly 200 of the tool 20 is shown.The drive assembly 200 includes a drive member 202, e.g., a rotatingdrive shaft. The drive member 202 is generally cylindrical in shape. Thedrive member 202 includes a cavity 204 (see FIG. 19) extending axiallyinwardly from a proximal end, a cavity 206 extending axially inwardlyfrom a distal end, and a passage 208 extending axially between thecavities 204 and 206. The drive member 202 includes a seal 210 disposedin the cavity 204 and a seal 212 disposed in the cavity 206. The drivemember 202 includes a flange 214 extending circumferentially andradially outward. The drive member 202 further includes a pair ofopposed flanges 216 extending axially from a proximal end. In theembodiment shown, the drive member 202 is integral, unitary, andone-piece, but could be separate parts in other embodiments. It shouldbe appreciated that the seal 210 seals against a rotatable shaft 252 ofan actuator 250 (see FIG. 21) to be described and the seal 212 sealsagainst the shaft 70 of the energy applicator 24. In the embodimentshown, the seal 212 may comprise a lip seal.

The drive assembly 200 also includes a driven member 218 coupled to thedrive member 202. The driven member 218 extends axially. The drivenmember 218 is generally cylindrical in shape. The driven member 218 isdisposed about the distal end of the drive member 202 and abuts theflange 214. In the embodiment shown, the driven member 218 is integral,unitary, and one-piece, but could be separate parts in otherembodiments.

The drive assembly 200 includes a drive connector 220 coupled to thedriven member 218 to rotate with the driven member 218. The driveconnector 220 is generally cylindrical in shape. The drive connector 220includes a cavity 222 extending axially inwardly from a proximal end anda cavity 224 extending axially inwardly from a distal end. The driveconnector 220 includes a flange 226 extending circumferentially andradially outward that abuts the distal end of the driven member 218. Inthe embodiment shown, the drive connector 220 is integral, unitary, andone-piece, but could be separate parts in other embodiments.

The drive assembly 200 further includes a clutch assembly 228 disposedwithin the driven member 218 and configured to slideably receive theshaft 70 of the energy applicator 24. The clutch assembly 228 issupported by the driven member 218 and rotatable relative to the drivemember 202. The clutch assembly 228 receives the shaft 70 of the energyapplicator 24 for selectively coupling the shaft 70 to the drive member202. Specifically, the shaft 70 is slideable into the clutch assembly228 and is slideable out of the clutch assembly 228.

With reference to FIGS. 16-20, the clutch assembly 228 includes aplurality of roller holders 230 spaced axially and disposed within thedriven member 218. Each of the roller holders 230 is generallycylindrical in shape. In the embodiment shown, each of the rollerholders 230 are generally disc-shaped. Each of the roller holders 230includes an interior aperture 232 extending axially therethrough. Eachof the roller holders 230 also includes opposed flanges 234 extendingradially inward. Each of the roller holders 230 includes a secondaryaperture 236 extending axially through one of the flanges 234 and spacedfrom the interior aperture 232. Each of the roller holders 230 includesa recess 238 extending radially into the opposing flange 234. In theembodiment shown, each of the roller holders 230 is integral, unitary,and one-piece, but could be separate parts in other embodiments. In oneembodiment, three roller holders 230 are disposed adjacent each other ata proximal end of the clutch assembly 228 and three roller holders 230are disposed adjacent each other at a distal end. These two sets ofroller holders 230 are spaced axially from one another and arecollectively referred to as a cage. Each of the three roller holders 230at each axial end are oriented so that their respective secondaryapertures 236 and recesses 238 are arranged approximately 120 degreescircumferentially relative to each other.

The clutch assembly 228 also includes a plurality of rollers 240 coupledto the roller holders 230. The rollers 240 extend axially. The rollers240 are generally cylindrical in shape. Each of the rollers 240 has ashaft 242 extending axially from each axial end. The two shafts 242 of afirst roller 240 are disposed in the apertures 236 of the two outermost(axially) roller holders 230, the two shafts 242 of a second roller 240are disposed in the apertures 236 of the two innermost (axially) rollerholders 230, and the two shafts 242 of a third roller 240 are disposedin the apertures 236 of the remaining two roller holders 230. Therollers 240 are arranged to be generally parallel to the shaft 70 of theenergy applicator 24 when the energy applicator 24 is coupled to thetool assembly 187.

The clutch assembly 228 also includes a plurality of counterweights 244coupled to the roller holders 230. The counterweights 244 extendaxially. The counterweights 244 are generally cylindrical in shape. Oneof the counterweights 244 is disposed in the recesses 238 of each pairof opposing roller holders 230, i.e., the two outermost roller holders230, the two innermost roller holders 230, and the remaining two rollerholders 230, so that there is one counterweight that corresponds to eachroller 240. It should be appreciated that the roller holders 230,rollers 240, and counterweights 244 are radially movable relative to theshaft 70 of the energy applicator 24.

The clutch assembly 228 further includes a pair of resilient members 246disposed about the rollers 240 and counterweights 244. The resilientmembers 246 are spaced axially from each other. The resilient members246 are of an O-ring type. The resilient members 246 are made of aflexible material. The resilient members 246 act to press the rollers240 against the shaft 70 during initial insertion of the shaft 70 intothe clutch assembly 228. During insertion, the shaft 70 is locatedradially inward of the rollers 240. The resilient members 246 provideenough biasing force so that once the shaft 70 is initially inserted,the rollers 240 frictionally engage and hold the shaft 70 from fallingout of the clutch assembly 228 due to gravity, i.e., before the axialconnector assembly 92 is moved back to the locked state to permanentlyhold the energy applicator 24 in place.

Referring to FIG. 20, in operation of the clutch assembly 228, whentorque is applied and the driven member 218 is rotated, an inner camsurface 251 of the driven member 218 rotates until the inner cam surface251 engages the rollers 240. More specifically, the driven member 218has a cross-sectional profile as shown in FIG. 20 that comprises a firstregion 251 a of thickness T1, a second region 251 b of thickness T2,which is less than T1, and the inner cam surface 251 is arcuate in shapefrom the first region 251 a to the second region 251 b to form camregions 251 c on either side of the second region 251 b (only onelabeled in FIG. 20). The cam regions 251 c, when rotated relative to theclutch assembly 228 (either direction) eventually engage the rollers 240and hold the rollers 240 against the shaft 70. In the embodiment shown,the outer surface of the driven member 218 is cylindrical.

During operation of the tool 20, the counterweights 244 oppose anycentrifugal forces that might otherwise act on the rollers 240 to pullthe rollers 240 away from the shaft 70. In other words, by virtue ofbeing heavier than the rollers 240, centrifugal forces acting on thecounterweights 244 are larger than those acting on the rollers 240thereby providing resultant forces that maintain contact of the rollers240 with the shaft 70, even at full speed. Roller 240/counterweight 244pairs are shown by dotted lines in FIG. 20 with their paired centers ofgravity CG illustrated. Thus, the clutch assembly 228 is counterweightedto maintain contact of the rollers 240 with the shaft 70 when torque isapplied to the driven member 218 by the actuator 250.

The counterweights 244 may be made of denser material than the rollers240. In one embodiment, the counterweights 244 are formed of tungstencarbide and the rollers 240 are formed of stainless steel. So, eventhough the counterweights 244 may be smaller in volume, they are heavierso that the center of gravity CG of each roller 240/counterweight 244pair is located closer to the counterweight 244. It should beappreciated that the clutch assembly 228 essentially floats inside thedriven member 218 with enough space to accommodate some radial and/oraxial movement of the roller holders 230, rollers 240, andcounterweights 244. In the embodiment shown, the clutch assembly 228comprises three clutch subassemblies, each subassembly comprising a pairof the roller holders 230 and one roller 240/counterweight 244 pairinterconnecting the pair of the roller holders 230. The clutchsubassemblies are able to shift relative to one another within thedriven member 218.

Referring to FIGS. 16 and 19, the drive assembly 200 includes a washer247 disposed between the seal 212 and the clutch assembly 228. The driveassembly 200 further includes bushings 248 disposed about the drivemember 202 and the drive connector 220 to support the drive member 202,driven member 218, drive connector 220, and clutch assembly 228 forrotation within the support structure 94. Bearings may be used in placeof one or more of the bushings 248 in some embodiments.

Referring to FIG. 21, the actuator 250 is coupled to the drive assembly200 to form a drive system. More specifically, the actuator 250 iscoupled to the drive member 202 to impart rotation to the drive member202. The actuator 250 is of a motor type and includes the shaft 252. Theshaft 252 engages the drive member 202 and the opposed flanges 216 torotate the drive member 202.

The support structure 94 further includes a floating collar or bushing150 disposed about and movable relative to the support sleeve 96. Thefloating collar 150 is generally cylindrical in shape. The floatingcollar 150 includes a raised portion 152 extending radially outward. Thesupport structure 94 includes a retaining ring 154 disposed in a groove156 (see FIG. 10) in the support sleeve 96 to distally retain axialmovement of the floating collar 150. It should be appreciated that thefloating collar 150 may be movable axially along and rotatably about thesupport sleeve 96. In the embodiment shown, the floating collar 150 isrotatable about the support sleeve 96 and generally axially constrainedbetween the retaining ring 154 and the lock collar 158.

The tool assembly 187 also includes an outer floating sheath 194rotatably disposed about a portion of the lock collar 158. The floatingsheath 194 is generally cylindrical in shape. The floating sheath 194includes a pair of flanges 196 (see FIGS. 3 and 12) spaced from oneanother and extending outwardly in an equal and parallel manner from anouter surface of the floating sheath 194. Each of the flanges 196includes an aperture 198 extending therethrough.

Referring to FIG. 3, a grip comprises a pair of grip members 258. Thegrip members 258 are sized and shaped to engage the floating collar 150and the second collar member 182 in a clam-shell manner about the outerfloating sheath 194 so that the grip is able to rotate relative to thesupport sleeve 96 during operation. A trigger 197 is pivotally connectedto the grip members 258 near a proximal end of the grip members 258 by asuitable mechanism such as a pin. During actuation, the trigger 197pivots relative to the grip members 258. The trigger 197 is also coupledto the outer floating sheath 194 by a link or lever 260 (see FIGS. 13and 14). More specifically, the lever 260 is pivotally connected at oneend to the flanges 196 of the outer floating sheath 194 by a suitablemechanism such as a pin. The other end of the lever 260 is pivotallyconnected to the trigger 197 at a location spaced from the pivotconnection of the trigger 197 with the grip members 258.

In operation, when the trigger 197 is depressed (toward the tool axisT), the trigger 197 applies a force on the link 260, which in turn movesthe link 260. The link 260 is arranged at an acute angle to the toolaxis T (see FIG. 14) such that the link 260 applies an axially-directedforce to the outer floating sheath 194 thereby moving the outer floatingsheath 194 toward the actuator 250. Since the outer floating sheath 194axially abuts the protrusions 178 of the first collar member 176, thefirst collar member 176 is also urged proximally. As previouslydescribed, the rods 190 are disposed in the recesses 179 of the firstcollar member 176 such that as the first collar member 176 movesproximally relative to the support sleeve 96, the rods 190 are alsopushed proximally. Proximal ends of the rods 190 are seated in pockets205 (see FIG. 3) in a switch actuator 207 such that proximal movement ofthe rods 190 causes the switch actuator 207 to also move proximally toactivate a switch (not shown). A spring (not shown) acts against theswitch actuator 207, rods 190, first collar member 176, link 260, and/orouter floating sheath 194 to return them to their pre-actuationposition. Depression of the trigger 197 may be required to energize theactuator 150, to switch between different modes, to enable operation ofthe tool 20, or the like. Other functions of the trigger 197 arecontemplated.

As noted above, another embodiment of the tool 20 is depicted in FIGS.22-25C. As will be appreciated from the subsequent description below,this embodiment is substantially similar to the embodiment illustratedin FIGS. 1-21, and both embodiments share similar structure andcomponents, as well as similar features, advantages, and operationaluse. Thus, common structure and components between the embodiments areprovided with the same reference numerals in the drawings and in thedescription below. Moreover, for the purposes of clarity, consistency,and brevity, certain structure and components common between theembodiments are not reintroduced or re-described below.

Referring now to FIGS. 22-25C, the illustrated embodiment of the tool 20similarly employs the tool assembly 187 to secure and drive the energyapplicator 24, which likewise has the axial-force receiving surface 77formed in the shaft 70. To this end, the tool assembly 187 similarlyemploys the support structure 94, the axial connector assembly 92, thedrive system 66 and clutch assembly 228, the collet assembly 157, thereference surface 189, and the protective sheath assembly 87. Each ofthese components, structural features, and assemblies generallycooperate to facilitate operation of the tool 20 in the same way asdescribed above in connection with the embodiment illustrated in FIGS.1-21, but are arranged and configured differently as described below.

As shown in FIGS. 22-23, the illustrated tool assembly 187 likewiseemploys the release member and the lock collar 158 of the colletassembly 157 to facilitate movement of the axial connector assembly 92between the locked state (see FIGS. 22, 24A, and 25A) and the unlockedstate (see FIGS. 23, 24C, and 25C). However, in this embodiment, thelock collar 158 is slidably movable relative to the support structure94. In order to facilitate sliding movement of the lock collar 158, therelease member is realized in this embodiment as a release lever 262which is coupled to the mounting fixture 64. Here, a release mechanism,generally indicated at 264, is interposed in force-translatingrelationship between the release lever 262 and the lock collar 158.

The release mechanism 264 comprises a pair of arms 266, an intermediatelink 268, and pins which cooperate to facilitate pivoting movement ofthe release lever 262 and the intermediate link 268 relative to themounting fixture 64. More specifically, an upper pin 269U, a lower pin269L, and a middle pin 269M are provided in the illustrated embodiment.The upper pin 269U is coupled to the mounting fixture 64 and supportsthe intermediate link 268 for pivoting relative to the mounting fixture64. The lower pin 269L (shown in phantom in FIGS. 22 and 23) is coupledto the release lever 262 and supports the intermediate link 268 forpivoting relative to the release lever 262. The middle pin 269M (shownin phantom in FIGS. 22 and 23) is coupled to the release lever 262 andis pivotally coupled to a portion 267 (shown in phantom in FIGS. 22 and23) of the mounting fixture 64. Each of the arms 266 has a first tab 270which engages the lock collar 158, and a second tab 272 which abuts theintermediate link 268. As shown in FIGS. 22-23, the arms 266 translatein a direction substantially parallel to the tool axis T in response topivoting movement of the intermediate link 268 resulting fromcorresponding movement of the release lever 262. It will be appreciatedthat the release mechanism 264 could be arranged for actuation by theuser in a number of different ways.

As shown in FIGS. 25A and 25C, the lock collar 158 is biased axially viathe spring member 168 which, in this embodiment, is realized as acylindrical compression spring interposed between the support sleeve 96and the lock collar 158 (see FIGS. 25A and 25C). As a result of theforce exerted on the lock collar 158 from the spring member 168, theaxial connector assembly 92 is biased toward the locked state. Inaddition to engaging and moving the lock collar 158, the arms 266 alsoengage and facilitate movement of the ring member 144 which, in turn,abuts the flanges 136 of the locking sleeve 130. Here, the lockingsleeve 130 is biased by the spring 188 and similarly moves axially tobring the engagement members 138 into abutment between the axial-forcereceiving surface 77 of the energy applicator 24 and the tapered orsloped surface 128 of the cam member 122 (see FIG. 24A).

As shown in FIGS. 24A-25C, in the illustrated embodiment, the drivenmember 218 is coupled to a drive sleeve 274 which, in turn, is coupledto the cam member 122 such that the driven member 218, the drive sleeve274, and the cam member 122 move concurrently. The drive sleeve 274rotates with the drive member 202 via a coupling arrangement, generallyindicated at 276, which may comprise a keyed, splined, or similararrangement of structural features which cooperate to engage andfacilitate concurrent rotation. Adjacent to the coupling arrangement276, a preload assembly 278 with a preload spring 280 and a collarmember 282 are provided. It will be appreciated that the driven member218 could be coupled to the drive member 202 in a number of differentways.

Referring again to FIGS. 22-25C, in the illustrated embodiment, thetrigger 197 is similarly arranged for actuation by the user. Here too,movement of the trigger 197 causes corresponding movement of the link orlever 260, which abuts and translates force to the outer floating sheath194. Here in this embodiment, the outer floating sheath 194 is disposedabout the support sleeve 96 and translates axially in response to forceacting on the trigger 197, and a trigger return mechanism 284 with areturn spring 285 facilitates limited, biased, axial movement of theouter floating sheath 194 relative to the support sleeve 96. As shown inFIGS. 24A-24B, the outer floating sheath 194 is shaped such thatmovement of the trigger 197 causes corresponding movement of a triggeractuator 286 (e.g., a ball bearing) supported by a portion of thetrigger return mechanism 284. Here, movement of the trigger actuator 286causes corresponding movement of a switch mechanism 288 (e.g., apiezoelectric switch) configured to facilitate operation of the toolassembly 187, such as by generating a variable signal used to effectcorresponding variable rotation of the actuator 250. However, it will beappreciated that the trigger 197 could be configured in a number ofdifferent ways sufficient to facilitate operation of the tool assembly187.

As noted above, the embodiment illustrated in FIGS. 22-25C also employsa removably-attachable protective sheath assembly 87. Here too in thisembodiment, the resilient member 116 biases one or more engagementmembers 114 toward the tool axis T and into engagement with the recesses164 formed in the protective sheath 80. It will be appreciated that anysuitable number of engagement members 114 could be employed to engage inany suitable number of recesses 164. In this embodiment, the protectivesheath assembly 87 comprises a pair of bearings 88 supported in theprotective sheath bore 82, a bearing biasing element 290, a spacer 292,and an end cap 294. Here, the spacer 292 is disposed between thebearings 88. The bearing biasing element 290 biases the bearings 88 andthe spacer 292 proximally toward the end cap 294. The end cap 294retains the bearings 88, the spacer 292, and the bearing biasing element290 within the protective sheath bore 82.

As shown in FIG. 24A, in this embodiment, a tag (e.g., a radio frequencyidentification tag RFID) is coupled to the end cap 294, and a reader 199is coupled to the connector member 120. Here, data (e.g., calibrationdata, usage data, and the like) that is stored on the tag RFID may beread by the reader 199 to, among other things, ensure that the properprotective sheath assembly 87 is being utilized for the surgicalprocedure, determine the expected life of and/or determine replacementor service of the protective sheath assembly 87 after a predeterminedamount of use, and the like. Data may also be written onto the tag RFIDvia the reader 199, such as to update the tag RFID after a surgicalprocedure with a new expected life, number of cycles, duration of use,and the like. Here too as shown in FIG. 24A, other tags RFID and/orreaders 199 may be employed to, among other things, identify thespecific energy applicator 24 being utilized via calibration data. Otherconfigurations are contemplated.

The embodiments of the systems 10 and tools 20 described herein affordsignificant advantages in connection with a broad number of medicaland/or surgical procedures including, for example, where surgicalmanipulators 14 are employed. Specifically, it will be appreciated thatthe embodiments of the tool assembly 187 described and illustratedherein are configured such that the energy applicator 24 can bereleasably attached in a simple, efficient, and reliable manner, and canbe driven to manipulate patient 12 tissue in a number of different waysto accommodate different surgical procedures, user preference, and thelike.

The present invention has been described in an illustrative manner. Itis to be understood that the terminology, which has been used, isintended to be in the nature of words of description rather than oflimitation. Many modifications and variations of the present inventionare possible in light of the above teachings. Therefore, the presentinvention may be practiced other than as specifically described.

1. A tool comprising: an energy applicator including a shaft extendingalong an axis between a proximal end and a distal end, said shaft havingan axial-force receiving surface; and a tool assembly comprising: asupport structure to support said energy applicator; an axial connectorassembly arranged to engage and releasably lock said energy applicatorto said support structure in a locked state; a drive system coupled tosaid support structure to rotatably drive said shaft of said energyapplicator about said axis; a collet assembly cooperating with saidaxial connector assembly and configured to apply a force to saidaxial-force receiving surface of said energy applicator in said lockedstate; and a reference surface, wherein said force includes an axialcomponent directing said energy applicator proximally into continuouscontact with said reference surface in said locked state.
 2. The tool asset forth in claim 1, wherein said collet assembly comprises a lockcollar movable relative to said support structure to move said axialconnector assembly from said locked state to an unlocked state.
 3. Thetool as set forth in claim 1, wherein said collet assembly comprises alock collar slidable relative to said support structure to move saidaxial connector assembly from said locked state to an unlocked state. 4.The tool as set forth in claim 2, wherein said axial connector assemblycomprises a cam member, a locking sleeve, and at least one engagementmember, wherein said at least one engagement member is arranged to applysaid axial component of said force to said axial-force receiving surfaceof said energy applicator when said axial connector assembly is in saidlocked state.
 5. The tool as set forth in claim 4, wherein said at leastone engagement member is further defined as a plurality of engagementmembers.
 6. The tool as set forth in claim 5, wherein said plurality ofengagement members are further defined as a plurality of ball bearings.7. The tool as set forth in claim 6, wherein said locking sleeve definesa plurality of openings extending radially therethrough to receive saidplurality of ball bearings.
 8. The tool as set forth in claim 4, whereinsaid cam member has a cam surface arranged at a first acute angle tosaid axis and said axial-force receiving surface is arranged at a secondacute angle to said axis, wherein said at least one engagement membercontacts both of said cam surface and said axial-force receiving surfacein said locked state; and wherein said first acute angle is differentthan said second acute angle.
 9. The tool as set forth in claim 8,wherein said first acute angle differs from said second acute angle in arange of from 6 to 10 degrees.
 10. The tool as set forth in claim 2,wherein said collet assembly includes a release member coupled to saidlock collar, said release member configured to be actuated by a user tomove said lock collar and place said axial connector assembly in saidunlocked state.
 11. The tool as set forth in claim 10, including aspring member cooperating with said lock collar to bias said lock collartoward a position in which said axial connector assembly is in saidlocked state.
 12. The tool as set forth in claim 1, wherein said drivesystem comprises a drive member and a counterweighted clutch assemblysupported by and selectively rotatable relative to said drive member,said counterweighted clutch assembly configured to receive said shaft ofsaid energy applicator for selectively coupling said shaft to said drivemember.
 13. The tool as set forth in claim 12, wherein said drive systemfurther comprises an actuator coupled to said drive member for rotatablydriving said drive member.
 14. The tool as set forth in claim 1,including an identification tag fixed to said proximal end of saidenergy applicator, wherein said tool assembly comprises a reader forcommunicating with said identification tag, said identification tagincluding calibration data.
 15. The tool as set forth in claim 1,wherein said shaft comprises an annular recess disposed between saidproximal end and said distal end with said annular recess being at leastpartially defined by said axial-force receiving surface.
 16. The tool asset forth in claim 15, wherein said axial-force receiving surfacecomprises a conical surface.
 17. The tool as set forth in claim 16,wherein said shaft has an outer surface and said annular recess has abottom, said conical surface extending a first axial distance from saidouter surface toward said bottom.
 18. The tool as set forth in claim 17,wherein said annular recess is at least partially defined by a distalsurface, said distal surface extending a second axial distance from saidouter surface toward said bottom, wherein said second axial distance isless than said first axial distance.
 19. The tool as set forth in claim1, wherein said axial-force receiving surface is arranged at an acuteangle relative to said axis, said acute angle being in a range of from 6to 14 degrees.
 20. The tool as set forth in claim 1, including aprotective sheath releasably coupled to said tool assembly to bearranged concentrically about said shaft of said energy applicator. 21.The tool as set forth in claim 20, including a bearing supported in saidprotective sheath such that said bearing is releasable, along with saidprotective sheath, from said tool assembly.
 22. A tool assembly for usewith an energy applicator having a shaft extending along an axis betweena proximal end and a distal end, the shaft having an axial-forcereceiving surface, said tool assembly comprising: a support structure tosupport said energy applicator; an axial connector assembly arranged toengage and releasably lock the energy applicator to said supportstructure in a locked state; a drive system coupled to said supportstructure to rotatably drive the shaft of the energy applicator aboutsaid axis; a collet assembly cooperating with said axial connectorassembly and configured to apply a force to the axial-force receivingsurface of the energy applicator when said axial connector assemblyengages and releasably locks the energy applicator to said supportstructure in said locked state; and a reference surface, wherein saidforce includes an axial component directing the energy applicatorproximally into continuous contact with said reference surface in saidlocked state.